Biotin appears in our formula at 5000mcg, which the label expresses as 16,667% of Daily Value. That percentage can look alarming, so let us explain exactly what it means and why we chose this dose.
The Daily Value for biotin is set at 30mcg — the amount needed to prevent deficiency. Supplementation studies for hair, skin and nail benefits use 2500–5000mcg, which is 83–167 times the DV. The high percentage reflects the DV being a floor, not a ceiling.
The NIH Office of Dietary Supplements notes no established Upper Tolerable Intake Level (UL) for biotin, meaning toxicity at high doses has not been demonstrated. Biotin is water-soluble; excess is excreted in urine rather than stored.
However, safety is not just about toxicity. The FDA has issued a safety communication warning that high-dose biotin can interfere with certain laboratory tests, including cardiac troponin (used to diagnose heart attacks) and thyroid panels. This interference can cause falsely normal or falsely abnormal results.
Inform every healthcare provider that you take a biotin supplement before any blood work. This is not optional advice — it is a safety requirement we take seriously enough to print on every page of our website.